Pyrex (trademarked as PYREX and pyrex) is a brand introduced by Corning Inc. in 1915 for a line of clear, low-thermal-expansion borosilicate glass used for laboratory glassware and kitchenware. It was later expanded to include kitchenware products made of soda-lime glass and other materials.

In 1998, the kitchenware division of Corning Inc. responsible for the development of Pyrex spun off from its parent company as Corning Consumer Products Company, subsequently renamed Corelle Brands (and would later merge with Instant Brands). Corning Inc. no longer manufactures or markets consumer products, only industrial ones.

Both trademarks, PYREX (all uppercase) and pyrex (all lowercase, introduced in 1975), were used interchangeably in the marketing of kitchenware products made of both borosilicate and soda lime glass, in addition to related accessories, for several decades.

The pyrex (all lowercase) trademark is now used for kitchenware sold in the United States, South America, and Asia. In Europe, Africa, and the Middle East, a variation of the PYREX (all uppercase) trademark is licensed by International Cookware for bakeware that has been made of numerous materials including borosilicate and soda-lime glass, stoneware, metal, plus vitroceramic cookware.

In the past, the brand name has also been used for kitchen utensils and bakeware by other companies in regions such as Japan and Australia.